156 



Frequent in still shallow waters of the central and western parishes. 

 The sterile fronds are prostrate and rest upon the surface of the water 

 or mud, the fertile are erect or erecto-spreading held up clear of the 

 water, and while the former are leafy and more or less subentire, the 

 latter are much divided, all the parts being narrow and linear or acicu- 

 lar. A transverse section of the stem shows numerous vascular bundles 

 mainly arranged at intervals on the outside, with abundant intervening 

 air channels. It possesses great fecundity, and multitudes of spores 

 germinate on moist surfaces, where the great majority eventually perish 

 from lack of water. It also grows from the axillary buds which are 

 produced by both kinds of fronds, though chiefly by the barren, those of 

 which, too, develop more constantly into leafage. Young barren plants 

 are often nearty covered by the pale developing plantlings that spring 

 from the surface buds. 



Tribe XYI. Osmundjeje. 



Sporangia crowded on the spikelets of contracted branch-like pinnae 

 or on the veins of the underside of normal ones, shortly stipitate, globose 

 reticulated, splitting vertically on one side when mature into open equal 

 valves, with a rudimentary transverse ring near the apex on the oppo- 

 site side. 



A small tribe consisting of only two genera Osmunda and Todea 

 which are widely separated in their geographical range, and beyond the 

 agreement in the character of the sporangia, have not much in common 

 in the physiognomy of their general features. One genus is confined to 

 the south temperate zone and the other principally to the north. The 

 rudimentary state of the ring, more globose form, and pedicellate base 

 of the sporangia distinguish this tribe from the next. 



Genus XXXVIII. Osmunda, Linn. 



Barren and fertile fronds, or portions of fronds, distinct ; the former 

 leafy, the latter mere rachises devoid of membrane, both compound ; 

 sori on the final ribs in contiguous sub-convolute or lobed spikelets, 

 veins free. 



The few species of Osmunda have their head quarters and chief range 

 in the north temperate zone, but three or four extend to the equator 

 and one even to the south temperate zone. Two species are found in 

 the West Indies both of which have a wide range both north and south 

 on the mainland. In all cases they are subaquatic or aquatic plants, in- 

 habiting marshes, flooded ditches or shallow ponds, the roots being 

 flooded and the fronds held erect above the water. 



Barren and fertile fronds separate. 



1. 0. cinnamomea. 

 Fronde fertile at the top ; the inferior pinnae barren, 



2. 0. regalis, 



1. 0, cinnamomea, Linn. — Eootstock upright or oblique; stipites 

 csespitose, erect, ^ - IJ ft. 1., flattened at the base, glabrous ; barren 

 fronds 1 - 2J ft. 1. in w., bi-pinnatifid, light green ; sub-coriaceous 

 the pinnge numerous, spreading, sub -distant in the lower part, 2 - 3 in. 

 1. ^ - f ths in. w., sessile and jointed at the base, the apex blunt, deeply 

 cut throughout into rounded segments which are 2 li. w., and rather 



